Revert "add overload to tuple.__new__ to better express an empty tuple (#7454)"

This reverts commit 64554bd.

Author: JelleZijlstra

stdlib/builtins.pyi

@@ -904,12 +904,7 @@ class slice:
     def indices(self, __len: SupportsIndex) -> tuple[int, int, int]: ...
 
 class tuple(Sequence[_T_co], Generic[_T_co]):
-    # overloads are ordered this way to pass `isinstance` checks
-    # see: https://github.com/python/typeshed/pull/7454#issuecomment-1061490888
-    @overload
-    def __new__(cls: type[Self], __iterable: Iterable[_T_co]) -> Self: ...
-    @overload
-    def __new__(cls) -> tuple[()]: ...
+    def __new__(cls: type[Self], __iterable: Iterable[_T_co] = ...) -> Self: ...
     def __len__(self) -> int: ...
     def __contains__(self, __x: object) -> bool: ...
     @overload